Lunar Scientists

Lunar Topographic Orthophotomap (LTO)

(glossary entry)

Description

A well regarded series of high resolution topographic maps of the lunar surface produced for NASA by the Defense Mapping Agency using stereo mapping of Apollo imagery. Contour lines are drawn on a photographic background. The maps are drawn at a scale of 1:250K (each unit of distance on the map represents 250,000 units of distance on the Moon), and each covers one-sixteenth of an LAC zone.

Additional Information

The complete series of published LTOs is available for free download from the Map Catalog (LTO) page of the LPI website.

The LTO charts introduced a number of provisional feature names that were never approved by the IAU. They also omit a number of letter crater names. Names appearing on the LTO charts should be viewed with caution.

Ashbrook (1974) describes the then-new LTO series and includes a list of names, with Gazetteer-style biographical ID's, supposedly adopted as titles for nearside LTO's by the IAU at its 1973 meeting in Sydney, Australia (IAU Transactions XVB). However the article also mentions certain new Latin feature type descriptor terms supposedly approved for use on the Moon (and specifically for use on the LTO's) even though there is no record of this in the IAU Transactions. These include Fossa (for graben-type rilles) -- a term currently used only on other bodies -- and two terms not currently used by the IAU on any body: Anguis (for snake-like rilles), and Ruina (for landslides).